Snitzerland's below-par performance in Saturday's Robert Sangster Stakes in Adelaide remains a mystery with trainer Gerald Ryan waiting on blood tests to determine whether she continues her autumn campaign.

The filly was the odds-on favourite to claim her first Group One victory at Morphettville but finished seventh, beaten three lengths, in the race won by Platelet.

Ryan said Snitzerland looked just as well after the race as she did before and he was mystified by the result.

"It was the worst run of her career," Ryan said.

"She was so bright and well before the race and just as good after. She looked even better than she did in Sydney.

"We're still waiting on the results of blood tests. If they reveal something wrong she will go to the paddock. If there's nothing there, then the Goodwood is still an option."

The $500,000 Group One Goodwood (1200m) on May 11 is South Australia's premier sprint.

Runner-up to star colt Pierro in the 2012 Golden Slipper, Snitzerland began her autumn campaign with victory in the Group Two Challenge Stakes.

She followed that with a second to Bel Sprinter in the Group One Galaxy on March 30.

Ryan was the trainer of Snitzerland's sire Snitzel and his success with the progeny of the 2006 Oakleigh Plate winner is renowned.

The trainer is looking to Amorino to become the next stakes winner from the stallion when he contests Saturday's Listed Hawkesbury Guineas.

"Both Craig Williams and Corey Brown who have ridden him at his past two starts, have told me he needs 1400 metres so we'll give him a go," Ryan said.

With both Williams and Brown riding in Asia for the next couple of months, Ryan had not yet engaged a jockey on Monday afternoon.

There were 17 entries for the Guineas one of three Listed races on the once-a-year Saturday program at Hawkesbury which replaces a metropolitan meeting.